/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/


new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve('hello');
    }, 100);
}).then(res => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(`${res} lagou`);
    }, 100);
  })
}).then(res => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(`${res} I ♥ U`);
      console.log(`${res} I ♥ U`);
    }, 100);
  })
})

